Lift truck



Feb. 24, 1942. G, QUAYLE 2,274,164

H LIFT TRUCK l' Filed Nov. 4, 1959 4 sheet's-shee't 1 M jim,

INVENTOR 5 @UF6-004,05

' ATTORNEY` v Feb. 24, 1 942.

' FiledNov. 4, 1939 4 sheets-sheet `2 'ATTORNEY G. QUAYLE LIFT TRUCKFeb. 24, 1942.

Filed Nov. 4, 1959 4 sheets-shet 3 INVENTOR faefagyzf BY ATTO FIN EYFeb. 24, I1942.

G. QUAYLE LIFT TRUCK Filed Nov. 4, 1939 4 Sheets--Sheefl 4 INVENTOR650665 7am/f ATTORNEY Patented- Feb.l 24. 1942' "Lnrifriwcir Y GeorgeQuayle, Philadelphia, Pa., assignorto The 1 Yale Towne ManufacturingCompany, Stamford, conmgacorporation of Connecticut 4, i939, semi-No.302,891

Application NovemberV sciaiins.l (Cien-2)" This invention relates toalifting-truck of the type inl which an' elevating platform islifted byan appropriate lifting mechanism. More particularly, this inventionrelates toa lifting-truck ofthe typedisclosed in the U; S. StuebingPatentV No. 1,785,368, owned yby The Yale 8x TowneMan-v ufacturingCompany, the .owner of this application.y Y Y Even more particularly,this inventionA relates toa lifting truck of the type in which thelifting platform is adapted to enter between the upper and lower floors.of a reversible skid platform or Y pallet, with l,the feature that whenthe platform `is elevated, the pallet :islifted pif the ground or flooron which it rests. .f

v'I'he truck which -I have conceived preferably, forms a unit separate'from the lifting n and reduced Y to practice utilizes an elevatingplatform which.

tion described hereinafter may be stood, and that the relation of mycontribution to the prior art maybe better appreciated. I` shall nowdescribethe preferred specific form-of my contribution to the art, itbeing understood,'of

course, that my contribution may be embodied in many specific forms bythose skilled in the art ,without vdeparting from the spiritand'substance,`

' thereof.

In the drawings, Fig. 1 is yan elevation of my ftruckywith certain partsshown infsection to similar to Fig. lwith the parts in the same re'-Vlation. showing the lifting platform of the truck head' through whichthe platformislifted. There lare means whereby the platform` isadapted.for

lifting movement `relatively to the lifting head lifting head. `Sincethe lifting head is at the front end of the truck. the said `meansholdingy the elevating platform in assembled relation tothe. liftinghead are at the frontend of the elevating platform, and I extend meansfrom'the said front end connecting meansto the rear of the truck foroperating means at the rear end ofthe plat- Y formwherebytosimultaneously lift the front andY rear endsof the platform.

.More particularly, in my-inventicn I employ 'a lifting head, which maybe ofany particular form having lifting mechanism, but which lispreferably the type shown inthe Stuebing Patent view similar to Fig. v2,showing the elevating 'platbetter illustrate their` operation. Fig. 2 isa ,view

located'. between the upper and lower iloors of'a reversible skidplatform or pallet.` Fig. 3 is -a form in elevated position. Fig. 4 is aview-looking downwardly on Figi: .1 with, the operating 'partsofthetruck platformexposed by the elimination of covering plates. Figs. 5 and6 are vwhile maintainedein assembled relation'to that respectivelylsections along linesl 5 5 .and H 1 of Fig. l. Flg.7 isaperspectiveviewV of thefront `end of the elevating platform and the partsconnecting that end of the platform tothe lifting head, taken somewhatalong the lines 5 5 of Fig. 1.

Referring now more particularly tothe draw-l ings, the lifting head ofmy vtruck'is designated by reference numeral I0, and maybe considered las, practically identical with the lifting head of i `the truck lshownin the siuebing Patent. No.

supra.v I providean elevatingplatform pivoted,f l preferably throughlinks. to thelifting head, wlth the feature 'that the platform. ismovablebythe lifting -means relatively' to lthe lifting head. flilat- "ourally, the liftingl means maylbe means acting toY separate Vthe liftingplatform and lifting head,y and thereby lifting theplatform. v l

Through the provision of linkage means which are actuated when the frontend of the .platformV is iified relatively to the iifting head, .wheelsan;

the rear 'of the .platform are simultaneously'- moved relativelyto theplatform andserve to.

lift the platform.V Preferably, theserear wheels are sov mounted thattheyfare capable of moving between the boards of av reversible.pa1lei'., soineA what in themanner disclosed in myaliplication for'patent SerialNo 184.918, nled January ifi, l' 19'38patented May 20,'1941' as Patent 2,242,432. v I have thus. described-generally mycontribu- 1,'185,368. ySince the construction of the'lifting.

vhead of the platformof my truck isV not in itself a .part of mycontribution to theart, I shall not in this specification venture'intomuchI detail in describing it, since those desiringto ascertain its jconstruction v may refer to the said Stuebing patent.`

- However, itvmay wenn, 'mainte t1-the lifting head comprises supporting`wheelsl l'. `-1 1d, a steering and lifting handle l2, downwardingmovement of which actualice a strut Il, which in turn vmoves a leverI4; on"zwhfich is mounted a -liftingjpawll il ooclierittixig with alifting: ratchet' il. witliftlielifting ratchetullare lifting links Il,,Ar-holding'pawl Il 'is` adapted, Q hold the lifting-ratchet yII in anypositionto whichlit 1 8 rotated-,by .the mll! pawl' I5. A controlling Itis manipulated by a- `foot treadle 2lto1"control thevrel'ea'se of thelifting pawi II and the holdlnapwl Il relatively toineiiitingratchet-is. v In one position-.of the t'readle 20 shown in tion totheart in order that the specific construc- 55 FIB'. V1, both the liftingand holding pawls are in contact with the lifting ratchet so that aseries of'downward swinging movements of the lifting handle I2 willrotate the ratchet I6 to rotate the lifting links I9 from their initialposition of Figs.

land 2 to their position of Fig. 3. Movement of the treadle 29 will,through the cam I8, move Yboth the lifting and holding pawls out ofcontact with the ratchet I6, and allow the lifting links I9 to move fromtheir position of Fig. 3 to their position of VFig. 1 incidental to thelowering movement of the elevating platform. So far as my contributionis concerned, it is merely neces-Y sary "to consider that the elevatingplatform is lifted as the lifting links I9 are rotated clockwise, andthat when the links I9 are released for counterclockwise movement, theelevating platform willbe moved to`- a lowered. position, as will bedescribed presently.

The elevating platform of my truck is l shaped, as best shown in Fig. 4,and comprises a pair. of identical platform legs 2| and a saddle 22.` Itwill of course be appreciated that for legs 2|, and the said saddleextends/vertically, asY

bestillustrated in Figs. 5 and '7, to a point 23.Y -At each side of t/hesaddle, somewhat below the portion 23 thereof, there are secured a pairof plates 24. EachV pair of plates 24 supports av pivot shaft 25 onwhich is pivoted a link 26. The other end of each link 26 is pivoted at'points 21 to-the liftinghead I0. g Ateach 4side ofrv the Vlower endofthe platform saddle, thereis secured a plate 28 `which supportsA voneendof a shaft 29.? Each of theshafts 29 extends fromiplate 28 through aside bar 30 of onev of the platform legs, through plates 3| and'32 ofthe saddle, and then through the other side bar 33 ofA the particularVplatform leg. Mounted on each of the shafts 29 is a pair of liftingstruts 34 which are secured by a pivot shaft 35 to each one of thelifting links I9 of the lifting head. It is therefore readily seen,especiall:1 from Figs. 1 and 1, that a clockwise rotation of the liftinglinks |9'will 'impart movement to the' lifting struts 34'to lift thesaddle 422 of the elevating platform throughshafts 29. I

Mounted on each of the shafts 29 between plates 3| and 32 of the saddleis a peculiarly shaped front end connecting link 36. Each front endconnecting link comprises av lever 31 welded as at 38 to a sleeve 39fitting about the shaft 29. Welded to the sleeve 39, or otherwisesuitably secured thereto, are aJ pair of ears 40 which in turnaresecured by a pivot shaft 4| to a rod 43 through a suitable clevis 44. Inorder to allow' for ready adjustment of the rod 43, it may b'e inthreaded relation to the clevis 44, as will be appreciated by thoseskilled in the art. Each lever 31 issecured vat its front end through apivot "shaft 45 tothe lifting head. I|I.` It will now be appreciatedthatV when the Ysaddle 22 moves vertically from the position of Figs. 1and 2 to the position ofFig. 3, the upper and lower connecting links26'and 36 will swing from their positions of Figs. l and 2 to theirposition of Y Fig. 3, and that this will effect movement of the rods '43to the rightilookingat Figs. 1, 2 and 3). This movement of rods 43is'utilized for lifting the rear end of the elevating platformsimultane-` ously with the front end thereof. For this purpose, each ofthe lifting legs 2| has pivoted thereto at 46 a rear lifting link 41,each carrying wheels 48. of course, secured in adjustable relation to aclevis 49 which is pivoteds at 5B to each of the links `41 to impartmovement thereto. As the rods 43 move to the right from the position ofFigs. l and 2 to the position of Fig. 3, the links 41 are rotatedcounterclockwise, and the wheels 48 are moved into the positions shownin Fig. 3,

thereby elevating the platform, as is self-evident. As was indicatedearlier in the specification, the truck of this invention is especiallydesigned lfor use with reversible pallets of the type disclosed `in myapplication"supra, the rear wheels 48 being intended to enter betweenthe boards 5I of a. reversible pallet for lifting the pallet, all as isshown in Figs., 2 and 3, In order that the truck may enter between theupper and lower floors of such a platform, I'equip the rear end of each\of the platform legs of my truck with a series`of rollers 52, whosepositions are so graduated that rst one of\the rollers will contact theplatform, thenthe second, and .then the third,

graduallly lifting each of the\platform legs intothe space between theupper and lower floors.

`VMoreover, rthe series of rollers 52 assistY in facilitating themovement of the truck to its position of-Fig.`2 relatively to thereversible pallet by cooperation witheach of the successive lower floorboards 5I. 1

Similarly, to assist in withdrawing the truck from between the upper andlower floors of a reversible pallet, I employ a further series of roll--ers 53, whose operation will be readily understood. Additional rollers54 further assist in the moi/ement of the platform legs 2I into and outI VYof the pallet.

Incidentally, it will be well to indicate at this AVtime that I 'utilizethe spread platform legs 2| because the floors of the usualtype ofreversible skid pallet are separated by a longitudinal beam, not hereinshown, the platform legs 2| being A adapted to enter the pallet on eachside of said longitudinal beam, all as is best setk forth in myapplication supra.

As I have already explained, lifting movement of theelevating platformof my truck is imparted thereto`by`vertical movement thereof on theupper and lower links '26 and 36 relatively to the lifting head I0.Those skilled in the art will well appreciate that the upper and lowerlifting links 26` and 36 act to maintain the platform in parallelogram'relationship to the lifting head IU, whereby so long as the platformlegs 2| comprising the lifting platform of the truck, are maine tainedparallel to the ground, the lifting head I0 will be maintainedperpendicular to the ground, all as is desirable in this art. Where thefloor is horizontal, the lifting head III will bemaintained in avertical plane, which is desirable for best operation thereof. Therelationship of the rear lifting links I41 to the upper and lowerlifting links 26 and 36 is, of course, preferably as has already beenindicated, so that the rear end of the elevating platform will be liftedat substantially the same rate as the front end thereof.

K Since, as has already been indicated, vertical movement of theelevating platform relatively to the lifting head I0 actsl to move 'thewheels'48 carried by the rearl lifting links 41, from the-posi tion ofFig. 2 toward the position lof Fig. 43, it will be readily appreciatedthat when the extreme rear rollers 52 of the platform legs 2| 'firstencounter a board 5| of the pallet, those rollers 52 will act tofliftthe 'pair of platform legs 2l and Each of the rods 43 is,

. Y 2,274,164 therefore the entire platform including the sad.

die 22, relatively tothe lifting head i0. Ihisis particularlyV true whenvusing mechanical lifting meansof the type herein disclosed, andwhichare readily movable through the .application of lifting pressure to theplatform. If this relative movement were not resisted, it would causetheV links 41 to rotate towards the position of Fig. r3,-

bringingthe wheels 4B down below their position in Fig. 2,- so .that thesaid wheels would forma lconsiderable obstruction against the` movementof 4the l'platform legs 2i further into-the space between the upper andlower floors 'of the reversible pallet. As a matter of fact, suchmovement of the wheels wouldfoifset all ofthe benefitsobtained by theutilization ofthe rollers 52',- and also of the rollers 53 and 54.

1. -I therefore provide springs 55 which are mount-rv ed about each ofthe rods 43 and press at Aone end against a plate 56 secured to the sidebars 30 other, ends, the springs v55 press 'against an "ade justablenut\51 on therods 43. 'I'he springs 55 .therefore function to preventrotation of the links Y 41 from'the position of Fig. 2 to the positionof Fig. 3 when the elevating platform is lifted relatively to thelifting head |0` throughv the applica-` v f tion'of lifting pressure tothe platform itself. Y

" Infthis way, when the platform is liftedr somee whatias inV the'position or Fig. 2, the wheels. 4s.

will notmove downwardly to obstruct the opera l tion ofthe rollers 52,53 and 54. Rather, the en'` tire .truck will pivot aboutthe wheels iiunder the .lifting head." Naturally, when the lifting mechanism itselfis actuated andthe lifting links I9 are rotated, moving the liftingstruts 34, there 2o and`33`of each of the platform legs 2|. At theirwill be a forceful separation between the lifting 'head i0 andthelifting platform, causing an up- 'ward movement of the -platform and acorresponding downward movement of the Awheels 48 wat the rear endsof'each ofthe platform legs 2|.V

In order to effect a smooth lowering of the'lifting platform when theholdingpawl .i1 is released, I employ a liquid dashpot 58 4of the typevstandard in this art. The plunger portion 58a ofthe dashpot 58. is'secured at its upper end unit about the n wheels headlmounted aboutsaid rods., whereby app cationof lifting pressure` to the said platformend to said liftinghead whereby to maintain a parallelogram.`arrangement between said links, said platform #and said lifting head,means for movlngtheplatform upwardly relatively to said f lifting headthrough said links,- rods extending from at least certainof said` linksfor moving vertically the wheels supporting the rear end of ,saidplatform whereby to lift simultaneouslythe frontfand rear ends of saidplatform, guide lugs on 'l said platform through which said rodsextend,.springs mounted about said rods and pressying at one end againstsaid lugs and at the other end against a stop on said rds, and saidsprings resisting said movement ofsaid platform relatively to said head,whereby application of lifting pressure to the said platform other thanthrough Y said lifting head means will merely tilt said platformand'lifting'head as a unit about the wheelsy supporting said liftinghead.

3. jIn alift truck; a lifting head, wheels supporting said lifting head,an elevating platform,

wheel supporting links plvoted to the -rear .end

of. said platformlinks secured at one end tothe front end of saidplatform and at their other end to thev lifting head whereby to form anassembled truck` and with the front end of the elevating lplatformsupported by said lifting head,'rods connecting said .rear wheelsupporting'links to "said front end links, means on said liftingv headporting links whereby to liftsimultaneously both n through suitablelinkage mechanism to a pair of angle irons l59 welded to the upper endof the v saddle 22 near the portionl 23 thereof, The lower end of thedashpot 5B is pivoted through a shaft l60 to the lowerV end 6| of abracket 62 which is secured as-4 by welding at 63 to the rear plate ofthe lifting head i 0. The dashpot 58 being mounted in the particularposition shownvery readily .follows the upward movement of the elevatingplatform and readily controls the downward lowering movement of theplatform. i

./'Having now described a preferred modification rf of my-invention,Iclaim 1. In a lift truck, alifting head, wheels s up- :porting saidlifting head, an elevating. platform, I

wheel -supporting linksgpivoted to the` rear end of said platform,supporting means securing the front end of said platform to the lifting'head whereby to form an assembled truck, rods connecting said rear'wheelsupporting links to said supporting meansmeans on'said. lifting headfor' moving said platform upwardly relatively to said lifting head andthroughsaid supporting means and thereby to effect a movement Vof .both,said Vsupporting means and said rear wheel supporting links. whereby toliftsimultaneously both Vends of said platform, and springs forresisting e movement of `said platform relatively to said for movingsaid platform upwardly relatively tol said lifting head 'and through'said front end links, and thereby. to effect a pivotal movement of saidfront end links and said rear wheel supends of said platform,"guide'lugs on said elevating platform for guiding' said rods, andsprings mounted on said'rods and pressing against said .guide lugs forresisting movement of said platform relativelyV to said head on saidlinks, whereby application of lifting pressure to the said platformother than through said lifting head means will merely tilt saidplatform and lifting head as e a unit. about the wheels supporting saidlifting head.

4. In alift truck, anfang head, wheels sup-nV porting said lifting head,an elevating platform, wheel supporting links pivotedto the rear endpf`said platform, supporting means securing the front end of said 4platformto' the lifting headwhereby to for-m anassembled truck, rodsy con.-

necting said rear wheel supporting links to said supporting means, guidelugs on said platform traversed by said rods, means o n said liftinghead for moving said platform upwardly relatively to j saidflifting headand through said supportingmeans, and thereby to effect movement of bothsaid supporting means'and said rear wheelsupporting links whereby tolift simultaneously both ends of said platform, rollers at the rear endof l said platform and rearwardly of said wheels whereby said rollerstend to lift said platform as vsaid rollers encounter an obstruction.and

springs mounted about said rods and pressing said plat/form, avertically extending saddle atthe front YendV of v said platform, upperand lower links each pivoted at one'end to said saddle and at theother..

against said guide lugs for resisting movement of said platform by saidrollers relatively to said head, whereby application oflifting pressureto the said platform by said rollers will merely tilt said platform andlifting head as a unit about the wheels supporting said lifting head.'

5. In a mozaiek of the cmssdescribed, a nrting head, an elevatingplatform having a vertical hollow standard juxtaposed to saidliftinghead and enclosing a portion of said lifting head, up-

. per and lower parallel links pivoted at their front ends'toy thelifting head and at their rear ends to"said standard, a `dashpotvertically disposed within said standard and pivoted at its lower en'dto'said lifting head and at its upper end to said standard, wheelsupporting links pivoted to the ing head, effects the rotation of saidlinks to lift the rear end of said platform, and means on said liftinghead for so lifting said platform.

rear of said elevating'platform,` means `connectfing said wheel=supporting -links to atleast certain of said parallel links wherebymovement of said parallel links'as the front end of said platform iselevated vrelatively to said/.lifting head, effects VVthe rotation ofsaid links to lift the rear end of vsaid platform, and means on saidlifting head for so lifting said platform. f,

6. In a lift truck of the class described, a lifting head, an elevatingplatform having a vertical hollow standard juxtaposedto said liftinghead,

upper andv lower parallellinks pivoted at their p frontendstolthe-lifting head and at their rear ends to said standard, adashpot vertically dis-` posed within said standard and pivoted at itslower end 'toY said lifting head and at its upper end to said standard,Wheel vsupporting links "pivoted to Vthe rear of said elevatingplatform, means connecting said wheel supporting links to at leastcertainof said parallel links whereby movement'of said of said platformis elevated relatively to said liftparallel links as thevfront end flib.

fz. rn a lift truck of the class described, a iiftend to said standard,wheel supporting links piv-` oted to the rear of said elevatingconnecting said wheel supporting platform, means links to at least'certain of said parallel links whereby movement of `said parallel linksas the front endof said platform is elevated relatively to said liftinghead, effects the rotation of said links to lift the Vrear end of saidplatform, and means extending between said lifting head and said lowerparallel links for actuating said links to lift said platform.

8. In a lift truck ofthe class described, a lifting head, an elevatingplatform having a vertical standard juxtaposed to said lifting head,upper and lower parallel links pivoted at their front ends to theliftinghead and at their rear ends t'o said standard, wheel supporting linkspivoted to the rear of said elevating platform, means connecting saidwheel supporting links to at least certain of said parallel linkswhereby movement of said parallellinks as the front end of said platformis elevated relatively to said lifting head, effects the rotation ofsaidlinks to lift the rear end of Asaid platform, and means extendingbetween said lifting head and said lower parallel links for actuatingsaid links to lift said platform.

GEORGE QUAYLE.

